KANSAS CITY, Mo. -- A neo-Nazi group has adopted a half-mile section of highway in Springfield as part of the state's litter prevention program.

The Springfield unit of the National Socialist Movement has committed to cleaning up trash along the section of Highway 160 near the city limits in west Springfield.

Two signs noting the group's membership in the Adopt-A-Highway program went up last October but drew attention only recently when the group picked up litter as part of a gathering in Springfield.

The state says it had no way to reject the group's application. A 2005 U.S. Supreme Court ruling arising from a similar effort by the Ku Klux Klan says membership in the Adopt-A-Highway program can't be denied because of a group's political beliefs.

"It's a First Amendment thing, and we can't discriminate as long as they pick up the trash," said Bob Edwards, a spokesman for the transportation department's office in Springfield.

The NSM Springfield unit decided to take part in the highway project because it wants to clean up the community, said Ariana Glass, a 16-year-old member of the youth division of the group.

"We wanted to prove that we're not out here just to have fun, we want to make the community look good," Glass said.

The group heard both honks of support and jeers when about 30 members and supporters picked up trash last Saturday. Greene County sheriff's deputies ticketed one man who group members say became threatening but there were no other incidents, she said.

"As far as I could see we got as much support and honks, people waving," Glass said.

Edwards said his department had received only one phone call asking why the group was allowed to adopt the highway. Louise Whall, spokeswoman for the city of Springfield, was not aware of the group's action until contacted by the AP, but said the city had no jurisdiction because it's a state program.

Members of the highway cleanup program are required to clean up trash at least four times a year. Edwards said about 600 groups pick up trash in the 12 counties surrounding Springfield.

In the early 2000s, Missouri went to the U.S. Supreme Court to fight efforts by the Ku Klux Klan to clean sections of state highways.

At the time, the state could reject applications for the Adopt-A-Highway program from groups that denied membership based on race or had a history of violence.

The Klan challenged those regulations and in 2000 the 8th U.S. Circuit Court of Appeals struck down the prohibitions.

The department adopted new highway cleanup rules, but a federal judge again ruled for the Klan in October 2003, saying the revised rules weren't substantially different than those previously struck down.

The state appealed, but was rejected by the U.S. Supreme Court in January 2005.

In general, the state can deny an organization's application only if it has members who have been convicted of violent criminal activity within the past 10 years.

After the state dropped the Klan from cleaning up a section of Interstate 55 near St. Louis in 2001 for failing to pick up trash, the stretch of highway was renamed the "Rosa Parks Highway" in honor of the black woman arrested in 1955 when she refused to give up her seat to a white man on a city bus in Montgomery, Ala.